They both fit in a 25-round multi-gauge ammo box from MTM Case-Gard. There are other configurations and sizes, but this box has a removable grate that keeps the vials from wiggling around. It comes in green and clear smoke with model number #S25D or #S-25-12D.
I learned about ammo boxes on FPN and ordered a few from Amazon at $4.50 a piece. Now my samples are sorted by brand though I might switch to color in future. My test tube racks have been retired as the ammo box is much more useful for storage purposes. Kudos to whoever discovered this find and posted about it on FPN.